In building construction, a firewall is a structure designed to incorporate building fires. As an example, an attic crawlspace that covers the entire length of the building would allow a fire to roar from one end of the building to the other. Breaking up the crawlspace with non-flammable walls helps to slow the spread of a fire.
Network firewalls have a alike function. A firewall is a network security strategy, either a program or a very device, that breaks up a network to integrate viruses and hackers.
Imagine two huge fish tanks side by side, divided by a wall. We want to grant the blue fish to mingle, but we require to keep the carnivorous fish on the left away from the baby fish on the proper. If we opened a computer-controlled door in the wall, programmed to only allow blue fish to pass but no one else, that would be a fishtank firewall.
Network firewalls 'segment" the network. Local traffic—the data that moves amid the computers in that segment—doesn't go through the firewall to the more prominent network outside. And data that doesn't must reach any person inside the firewall is blocked out, just like the carnivorous fish in our example.
A Proxy is another network security tool. Proxies are replacements for Internet servers. When a computer requests a web-site from the net, a main hub provides the IP address. A firewall can interfere with this, and declare that no one inside the firewall may surf the Internet. The Proxy is then the "official" way past the firewall.
A proxy server has a list of "authorized" sites. When the user's computer requests the address from the Internet, the proxy checks it against the list, and whether or not the internet site is approved, it authorizes the firewall to let the traffic through. If the web-site is not approved, then the firewall sends a message saying "you aren’t authorized to visit this internet-location. "
